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Long interspersed element 1 (LINE-1) open reading frame 1 protein (ORF1p) expression is a common feature of many cancer types, including high-grade serous ovarian carcinoma (HGSOC). Here, we report that ORF1p is not only expressed but also released by ovarian cancer and primary tumor cells. Immuno-multiple reaction monitoring-mass spectrometry assays showed that released ORF1p is confidently detectable in conditioned media, ascites, and patients' plasma, implicating ORF1p as a potential biomarker. Interestingly, ORF1p expression is detectable in fallopian tube (FT) epithelial precursors of HGSOC but not in benign FT, suggesting that ORF1p expression in an early event in HGSOC development. Finally, treatment of FT cells with DNA methyltransferase inhibitors led to robust expression and release of ORF1p, validating the regulatory role of DNA methylation in LINE-1 repression in non-tumorigenic tissue., (© 2023. The Author(s).)

Ovarian immature teratoma is a rare subtype of germ cell tumour that can be pure or associated with non-teratomatous germ cell tumour elements and is graded based on extent of the immature neuroectodermal component. Immature teratoma (IT) can also be associated with somatic differentiation in the form of sarcoma, carcinoma, or extensive immature neuroectodermal elements and may produce low levels of serum alpha-fetoprotein. Variable interpretation of these issues underlies diagnostic and management dilemmas, resulting in substantial practice differences between paediatric and adult women with IT. The Malignant Germ Cell International Consortium (MaGIC) convened oncologists, surgeons, and pathologists to address the following crucial clinicopathologic issues related to IT: (1) grading of IT, (2) definition and significance of 'microscopic' yolk sac tumour, (3) transformation to a somatic malignancy, and (4) interpretation of serum tumour biomarkers. This review highlights the discussion, conclusions, and suggested next steps from this clinicopathologic conference., Competing Interests: Conflict of interest statement The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Primary peritoneal malignant mesothelioma (MM) can demonstrate morphologic overlap with low-grade and high-grade tubo-ovarian serous neoplasms; it is also biologically and prognostically distinct from benign mesothelial proliferations. Currently, there is no single biomarker that can definitively distinguish these neoplasms. Sex-determining region Y box 6 (SOX6) immunohistochemistry has been recently described to differentiate pleural epithelioid MM from lung adenocarcinoma, but it has not been evaluated in the peritoneum. SOX6 immunohistochemistry was performed on 43 peritoneal epithelioid MM, 7 peritoneal biphasic MM, 5 well-differentiated papillary mesotheliomas, 5 serous borderline tumors, 29 low-grade serous carcinomas (LGSCs), 20 high-grade serous carcinomas (HGSCs), and 25 cases of peritoneal reactive mesothelial hyperplasia. Quantitative SOX6 expression in epithelioid MM (median, 100% of tumor cells) was significantly greater than in LGSC/serous borderline tumor (median, 90%; P=0.004) and HGSC (median, 45%; P=0.0001). However, when SOX6 is expression is defined as ≥10% of tumor cells, there was no significant difference in the rate of SOX6 positivity between epithelioid MM (41/43, 95%), LGSC (28/29, 97%; P=1.0), and HGSC (17/20, 85%; P=0.16). Quantitative extent of SOX6 expression in epithelioid MM was significantly greater than in biphasic MM (median, 0%; P=0.0001), well-differentiated papillary mesothelioma (median, 20%; P=0.001), and reactive mesothelial hyperplasia (median, 20%; P=0.0001), but not significantly different from flat quiescent mesothelium (median, 90%; P=0.82). SOX6 immunohistochemistry is 95% sensitive for peritoneal epithelioid MM, but is also consistently expressed in LGSC and HGSC, negating its usefulness in this common differential diagnosis. SOX6 also shows variable expression across the spectrum of reactive, benign neoplastic, and malignant mesothelial lesions of the peritoneum, and does not appear to be diagnostically useful in distinguishing benign from malignant mesothelial proliferations., Competing Interests: Conflicts of Interest and Source of Funding: D.B.C.’s work is supported by the Ovarian Cancer Research Alliance (Ann Schreiber Mentored Investigator Award; grant no. 650320). For M.S.H. none were declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

A chemotherapy response score (CRS) system was recently described to assess the histopathologic response and prognosis of patients with tubo-ovarian high-grade serous carcinoma (HGSC) receiving neoadjuvant chemotherapy. The current study was performed as an independent assessment of this CRS system. We retrospectively identified advanced stage HGSC patients who received neoadjuvant chemotherapy and underwent interval debulking. If available, a hemotoxylin and eosin slide from the omentum and the adnexa was selected for the study. Slides were independently scored by 13 pathologists using the 3-tiered CRS system. Reviewers then received web-based training and rescored the slides. Overall survival and progression-free survival were estimated using the Kaplan-Meier method and compared using the log-rank test. A total of 68 patients with omental (n=65) and/or adnexal (n=59) slides were included in the study. Interobserver reproducibility was moderate for omentum (κ, 0.48) and poor for adnexa (κ, 0.40), which improved for omentum (κ, 0.62) but not for adnexa (κ, 0.38) after online training. For omental slides, a consensus CRS of 1/2 was associated with a shorter median progression-free survival (10.9 mo; 95% confidence interval, 9-14) than a CRS of 3 (18.9 mo; 95% CI, 18-24; P=0.020). In summary, a 3-tiered CRS system of hemotoxylin and eosin-stained omental deposits can yield prognostic information for HGSC patients receiving neoadjuvant chemotherapy, and web-based training improved reproducibility but did not alter determination of clinical outcomes. The CRS system may allow oncologists to identify potential nonresponders and triage HGSC patients for heightened observation and/or clinical trials.

Recent insights supporting the fallopian tube epithelium (FTE) and serous tubal intraepithelial carcinomas (STIC) as the tissue of origin and the precursor lesion, respectively, for the majority of high-grade serous ovarian carcinomas (HGSOC) provide the necessary context to study the mechanisms that drive the development and progression of HGSOC. Here, we investigate the role of the E3 ubiquitin ligase RNF20 and histone H2B monoubiquitylation (H2Bub1) in serous tumorigenesis and report that heterozygous loss of RNF20 defines the majority of HGSOC tumors. At the protein level, H2Bub1 was lost or downregulated in a large proportion of STIC and invasive HGSOC tumors, implicating RNF20/H2Bub1 loss as an early event in the development of serous ovarian carcinoma. Knockdown of RNF20, with concomitant loss of H2Bub1, was sufficient to enhance cell migration and clonogenic growth of FTE cells. To investigate the mechanisms underlying these effects, we performed ATAC-seq and RNA-seq in RNF20 knockdown FTE cell lines. Loss of RNF20 and H2Bub1 was associated with a more open chromatin conformation, leading to upregulation of immune signaling pathways, including IL6. IL6 was one of the key cytokines significantly upregulated in RNF20- and H2Bub1-depleted FTE cells and imparted upon these cells an enhanced migratory phenotype. These studies provide mechanistic insight into the observed oncogenic phenotypes triggered by the early loss of H2Bub1. SIGNIFICANCE: Loss of RNF20 and H2Bub1 contributes to transformation of the fallopian tube epithelium and plays a role in the initiation and progression of high-grade serous ovarian cancer. Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/4/760/F1.large.jpg., (©2018 American Association for Cancer Research.)

Mucinous ovarian tumors (MOTs) morphologically and epidemiologically resemble mucinous cystic neoplasms (MCNs) of the pancreas, sharing a similar stroma and both occurring disproportionately among young females. Additionally, MOTs and MCNs share similar clinical characteristics and immunohistochemical phenotypes. Exome sequencing has revealed frequent recurrent mutations in KRAS and RNF43 in both MOTs and MCNs. The cell of origin for these tumors remains unclear, but MOTs sometimes arise in the context of mature cystic teratomas and other primordial germ cell (PGC) tumors. We undertook the present study to investigate whether non-teratoma-associated MOTs and MCNs share a common cell of origin. Comparisons of the gene expression profiles of MOTs [including both the mucinous borderline ovarian tumors (MBOTs) and invasive mucinous ovarian carcinomas (MOCs)], high-grade serous ovarian carcinomas, ovarian surface epithelium, Fallopian tube epithelium, normal pancreatic tissue, pancreatic duct adenocarcinomas, MCNs, and single-cell RNA-sequencing of PGCs revealed that both MOTs and MCNs are more closely related to PGCs than to either eutopic epithelial tumors or normal epithelia. We hypothesize that MCNs may arise from PGCs that stopped in the dorsal pancreas during their descent to the gonads during early human embryogenesis, while MOTs arise from PGCs in the ovary. Together, these data suggest a common pathway for the development of MCNs and MOTs, and suggest that these tumors may be more properly classified as germ cell tumor variants. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd., (Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.)

Mature teratomas are the most common ovarian neoplasms, accounting for 40% to 50% of ovarian tumors, and are histologically defined by the presence of multiple lineages of mature differentiated cells derived from one or more of the 3 embryonic germ layers; ectoderm, mesoderm, and endoderm. Neuroectodermal and neural crest differentiation can be observed in mature teratomas, but it is uncommon to find secondary tumors that arise from the neural crest lineage. Herein we report the uncommon finding of a ganglioneuroma arising in a mature cystic teratoma in a 26-yr-old woman.

Purpose: A major challenge in platinum-based cancer therapy is the clinical management of chemoresistant tumors, which have a largely unknown pathogenesis at the level of epigenetic regulation. Experimental Design: We evaluated the potential of using global loss of 5-hydroxymethylcytosine (5-hmC) levels as a novel diagnostic and prognostic epigenetic marker to better assess platinum-based chemotherapy response and clinical outcome in high-grade serous tumors (HGSOC), the most common and deadliest subtype of ovarian cancer. Furthermore, we identified a targetable pathway to reverse these epigenetic changes, both genetically and pharmacologically. Results: This study shows that decreased 5-hmC levels are an epigenetic hallmark for malignancy and tumor progression in HGSOC. In addition, global 5-hmC loss is associated with a decreased response to platinum-based chemotherapy, shorter time to relapse, and poor overall survival in patients newly diagnosed with HGSOC. Interestingly, the rescue of 5-hmC loss restores sensitivity to platinum chemotherapy in vitro and in vivo , decreases the percentage of tumor cells with cancer stem cell markers, and increases overall survival in an aggressive animal model of platinum-resistant disease. Conclusions: Consequently, a global analysis of patient 5-hmC levels should be included in future clinical trials, which use pretreatment with epigenetic adjuvants to elevate 5-hmC levels and improve the efficacy of current chemotherapies. Identifying prognostic epigenetic markers and altering chemotherapeutic regimens to incorporate DNMTi pretreatment in tumors with low 5-hmC levels could have important clinical implications for newly diagnosed HGSOC disease. Clin Cancer Res; 24(6); 1389-401. ©2017 AACR ., (©2017 American Association for Cancer Research.)

High-grade serous ovarian carcinoma (HGSOC) is the most frequent type of ovarian cancer and has a poor outcome. It has been proposed that fallopian tube cancers may be precursors of HGSOC but evolutionary evidence for this hypothesis has been limited. Here, we perform whole-exome sequence and copy number analyses of laser capture microdissected fallopian tube lesions (p53 signatures, serous tubal intraepithelial carcinomas (STICs), and fallopian tube carcinomas), ovarian cancers, and metastases from nine patients. The majority of tumor-specific alterations in ovarian cancers were present in STICs, including those affecting TP53, BRCA1, BRCA2 or PTEN. Evolutionary analyses reveal that p53 signatures and STICs are precursors of ovarian carcinoma and identify a window of 7 years between development of a STIC and initiation of ovarian carcinoma, with metastases following rapidly thereafter. Our results provide insights into the etiology of ovarian cancer and have implications for prevention, early detection and therapeutic intervention of this disease.

A key feature of high-grade serous ovarian carcinoma (HGSOC) is frequent amplification of the 3q26 locus harboring PRKC-ι ( PRKCI ). Here, we show that PRKCI is also expressed in early fallopian tube lesions, called serous tubal intraepithelial carcinoma. Transgenic mouse studies establish PRKCI as an ovarian cancer-specific oncogene. Mechanistically, we show that the oncogenic activity of PRKCI relates in part to the up-regulation of TNFα to promote an immune-suppressive tumor microenvironment characterized by an abundance of myeloid-derived suppressor cells and inhibition of cytotoxic T-cell infiltration. Furthermore, system-level and functional analyses identify YAP1 as a downstream effector in tumor progression. In human ovarian cancers, high PRKCI expression also correlates with high expression of TNFα and YAP1 and low infiltration of cytotoxic T cells. The PRKCI-YAP1 regulation of the tumor immunity provides a therapeutic strategy for highly lethal ovarian cancer., (© 2017 Sarkar et al.; Published by Cold Spring Harbor Laboratory Press.)

The vast majority of ovarian cancer-related deaths are caused by metastatic dissemination of tumor cells, resulting in subsequent organ failure. However, despite our increased understanding of the physiological processes involved in tumor metastasis, there are no clinically approved drugs that have made a major impact in increasing the overall survival of patients with advanced, metastatic ovarian cancer. We identified prosaposin (psap) as a potent inhibitor of tumor metastasis, which acts via stimulation of p53 and the antitumorigenic protein thrombospondin-1 (TSP-1) in bone marrow-derived cells that are recruited to metastatic sites. We report that more than 97% of human serous ovarian tumors tested express CD36, the receptor that mediates the proapoptotic activity of TSP-1. Accordingly, we sought to determine whether a peptide derived from psap would be effective in treating this form of ovarian cancer. To that end, we developed a cyclic peptide with drug-like properties derived from the active sequence in psap. The cyclic psap peptide promoted tumor regression in a patient-derived tumor xenograft model of metastatic ovarian cancer. Thus, we hypothesize that a therapeutic agent based on this psap peptide would have efficacy in treating patients with metastatic ovarian cancer., (Copyright © 2016, American Association for the Advancement of Science.)

Objective: To credential Stathmin 1 (STMN1) and p16(INK4A) (p16) as adjunct markers for the diagnosis of serous tubal intraepithelial carcinoma (STIC), and to compare STMN1 and p16 expression in p53-positive and p53-negative STIC and invasive high-grade serous carcinoma (HGSC)., Methods: Immunohistochemistry (IHC) was used to examine STMN1 and p16 expression in fallopian tube specimens (n=31) containing p53-positive and p53-negative STICs, invasive HGSCs, and morphologically normal FTE (fallopian tube epithelium). STMN1 and p16 expression was scored semiquantitatively by four individuals. The semiquantitative scores were dichotomized, and reported as positive or negative. Pooled siRNA was used to knockdown p53 in a panel of cell lines derived from immortalized FTE and HGSC., Results: STMN1 and p16 were expressed in the majority of p53-positive and p53-negative STICs and concomitant invasive HGSCs, but only scattered positive cells were present in morphologically normal FTE. Both proteins were expressed consistently across multiple STICs from the same patient and in concomitant invasive HGSC. Knockdown of p53 in immortalized FTE cells and in four HGSC-derived cell lines expressing different missense p53 mutations did not affect STMN1 protein levels., Conclusions: This study demonstrates that STMN1 and p16 are sensitive and specific adjunct biomarkers that, when used with p53 and Ki-67, improve the diagnostic accuracy of STIC. The addition of STMN1 and p16 helps to compensate for practical limitations of p53 and Ki-67 that complicate the diagnosis in up to one third of STICs., (Copyright © 2015 Elsevier Inc. All rights reserved.)

The fallopian tube is now generally considered the dominant site of origin for high-grade serous ovarian carcinoma. However, the molecular pathogenesis of fallopian tube-derived serous carcinomas is poorly understood and there are few experimental studies examining the transformation of human fallopian tube cells. Prompted by recent genomic analyses that identified cyclin E1 (CCNE1) gene amplification as a candidate oncogenic driver in high-grade serous ovarian carcinoma, we evaluated the functional role of cyclin E1 in serous carcinogenesis. Cyclin E1 was expressed in early- and late-stage human tumor samples. In primary human fallopian tube secretory epithelial cells, cyclin E1 expression imparted malignant characteristics to untransformed cells if p53 was compromised, promoting an accumulation of DNA damage and altered transcription of DNA damage response genes related to DNA replication stress. Together, our findings corroborate the hypothesis that cyclin E1 dysregulation acts to drive malignant transformation in fallopian tube secretory cells that are the site of origin of high-grade serous ovarian carcinomas., (©2013 AACR.)

Background: Due to concern that mucinous malignant or borderline ovarian neoplasms (MON) may represent metastatic deposits from appendiceal primaries, gynecologic oncologists routinely perform appendectomy in these cases. However, a multidisciplinary critique of this practice is lacking., Methods: The New England Case-Control study database was utilized to compare the effect of prior appendectomy against known risk factors for MON. Pathology and operative reports of local cases of MON were reviewed to estimate the frequency of microscopic mucinous lesions in the appendix. Protein expression patterns among mucinous ovarian, colorectal, and appendiceal cancers were compared by immunohistochemistry., Results: From the New England Case-Control study, 287 cases of MON were compared against 2339 age-matched controls. Prior appendectomy did not reduce the risk of MON (OR 1.28, 95% CI 0.83-1.92, p = 0.23), while prior tubal ligation, parity, and breastfeeding were each protective against MON. Active smoking (OR 2.04, 95% CI 1.48-2.80, p < 0.001) was associated with an increased risk of MON. Among 196 mucinous adnexal tumors, appendectomy did not reclassify any MON as appendiceal in origin. By immunohistochemistry, mucinous ovarian carcinomas tended to be CK7+/CK20-/MUC2-/CDX2-, whereas mucinous colorectal and appendiceal adenocarcinomas were typically CK7-/CK20+/MUC2+/CDX2+, although with some overlap in immunophenotype. Additionally, PAX8 was positive in a subset of MOC and negative in all appendiceal carcinomas., Conclusion: Prior appendectomy is not protective against development of malignant or borderline MON. Routine appendectomy during surgery for MON seldom reveals an unsuspected GI primary in early stage tumors but may aid in final diagnosis in advanced stage cases., Funding: National Cancer Institute grants P50-CA105009 and R21 CA-156021; The Honorable Tina Brozman 'Tina's Wish' Foundation; the Dr. Miriam and Sheldon G. Adelson Medical Research Foundation (AMRF); Dana-Farber Cancer Institute - Susan Smith Center for Women's Cancers; Robert and Deborah First Fund; The Gamel Family Fund; Mary Kay Foundation; Sandy Rollman Ovarian Cancer Foundation; Arthur Sachs/Fulbright/Harvard; La Fondation Philippe; La Fondation de France., (Copyright © 2013 Elsevier Inc. All rights reserved.)

High-grade serous ovarian carcinoma presents significant clinical and therapeutic challenges. Although the traditional model of carcinogenesis has focused on the ovary as a tumor initiation site, recent studies suggest that there may be additional sites of origin outside the ovary, namely the secretory cells of the fallopian tube. Our study demonstrates that high-grade serous tumors can originate in fallopian tubal secretory epithelial cells and also establishes serous tubal intraepithelial carcinoma as the precursor lesion to high-grade serous ovarian and peritoneal carcinomas in animal models targeting the Brca, Tp53, and Pten genes. These findings offer an avenue to address clinically important questions that are critical for cancer prevention and early detection in women carrying BRCA1 and BRCA2 mutations., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Serous tubal intraepithelial carcinoma (STIC) is a noninvasive phase of pelvic serous cancer at risk for metastasizing. Because of its biologic significance, its accurate distinction from nonmalignant mimics is important. Loss of cell orientation is an important feature of STIC. We sought to determine whether the immunohistochemical localization of cytoskeletal-organizing proteins phospho-ezrin-radaxin-moesin (p-ERM) would be useful in making this distinction. The benign oviductal entities (normal and p53 signatures), premalignant atypias (tubal intraepithelial lesions in transition), serous intraepithelial carcinomas (STICs), and carcinomas were analyzed for 5 staining patterns and compared. Linear or uniform luminal p-ERM staining was strongly associated with benign mucosa in contrast to STICs, in which it was lost and often replaced by nonlinear or nonuniform patterns highlighting individually cell groups or single cells. Premalignant atypias were similar to benign mucosa by p-ERM staining and retained the linear luminal pattern. This study shows, for the first time, that patterns of staining for an immunohistochemical correlate of cell polarity (p-ERM) differ between STICs, their benign counterparts and premalignant atypias that do not fulfill the criteria for STICs. If confirmed, these findings warrant further analysis of indices of cell polarity as objective markers for the diagnosis and mapping of the evolution of pelvic serous precursors.

The comprehensive characterization of a large number of cancer genomes will eventually lead to a compendium of genetic alterations in specific cancers. Unfortunately, the number and complexity of identified alterations complicate endeavors to identify biologically relevant mutations critical for tumor maintenance because many of these targets are not amenable to manipulation by small molecules or antibodies. RNA interference provides a direct way to study putative cancer targets; however, specific delivery of therapeutics to the tumor parenchyma remains an intractable problem. We describe a platform for the discovery and initial validation of cancer targets, composed of a systematic effort to identify amplified and essential genes in human cancer cell lines and tumors partnered with a novel modular delivery technology. We developed a tumor-penetrating nanocomplex (TPN) that comprised small interfering RNA (siRNA) complexed with a tandem tumor-penetrating and membrane-translocating peptide, which enabled the specific delivery of siRNA deep into the tumor parenchyma. We used TPN in vivo to evaluate inhibitor of DNA binding 4 (ID4) as a novel oncogene. Treatment of ovarian tumor-bearing mice with ID4-specific TPN suppressed growth of established tumors and significantly improved survival. These observations not only credential ID4 as an oncogene in 32% of high-grade ovarian cancers but also provide a framework for the identification, validation, and understanding of potential therapeutic cancer targets.

Ovarian cancer is the fifth leading cause of cancer death for women in the U.S. and the seventh most fatal worldwide. Although ovarian cancer is notable for its initial sensitivity to platinum-based therapies, the vast majority of patients eventually develop recurrent cancer and succumb to increasingly platinum-resistant disease. Modern, targeted cancer drugs intervene in cell signaling, and identifying key disease mechanisms and pathways would greatly advance our treatment abilities. In order to shed light on the molecular diversity of ovarian cancer, we performed comprehensive transcriptional profiling on 129 advanced stage, high grade serous ovarian cancers. We implemented a, re-sampling based version of the ISIS class discovery algorithm (rISIS: robust ISIS) and applied it to the entire set of ovarian cancer transcriptional profiles. rISIS identified a previously undescribed patient stratification, further supported by micro-RNA expression profiles, and gene set enrichment analysis found strong biological support for the stratification by extracellular matrix, cell adhesion, and angiogenesis genes. The corresponding "angiogenesis signature" was validated in ten published independent ovarian cancer gene expression datasets and is significantly associated with overall survival. The subtypes we have defined are of potential translational interest as they may be relevant for identifying patients who may benefit from the addition of anti-angiogenic therapies that are now being tested in clinical trials.

High-grade endometrioid and serous carcinomas of the ovary and fallopian tube are responsible for the majority of cancer deaths and comprise a spectrum that includes early or localized (tubal intraepithelial carcinoma) and advanced (invasive or metastatic) disease. We subdivided a series of these tumors into three groups, (1) classic serous, (2) mixed serous and endometrioid and (3) endometrioid carcinomas and determined: (1) the frequencies of coexisting tubal intraepithelial carcinoma, (2) frequency of a dominant ovarian mass suggesting an ovarian origin and (3) immuno-localization of WT-1, p53, PTEN, PAX2 and p16(ink4). All tumors were analyzed for p53 mutations. Thirty six, 25 and 8% of groups 1-3 were associated with tubal intraepithelial carcinoma (P=0.09) and 34, 45 and 62% predominated in one ovary (P=0.028), respectively. Differences in frequencies of diffuse p53 immunostaining (85-93%), WT-1 (70-98%) and p16(ink4) positivity (69-75%) were not significant for all groups. Greater than 95% reduction in PAX2 and PTEN occurred in 67-75 and 5-12%, respectively; however, PAX2 and PTEN staining intensity, when present, was often heterogeneous, highlighting different tumor populations. PAX2 and PTEN expression were markedly reduced or absent in 12 of 12 and 4 of 12 tubal intraepithelial carcinomas. In summary, high-grade müllerian carcinomas share identical frequencies of altered or reduced expression of p53, PTEN and PAX2, all of which can be appreciated in tubal intraepithelial carcinomas. Because only a subset of these tumors appears to arise in the fallopian tube, attention to expression of these biomarkers in the ovary and other müllerian sites might facilitate the identification of other carcinogenic pathways. PAX2 and PTEN, in addition to p53 and p16(ink4), comprise a potentially important gene combination in high-grade pelvic carcinogenesis.

Ovarian serous neoplasms can have morphologic overlap with malignant mesothelioma. The distinction is clinically important, yet most studies have failed to identify immunostains that reliably distinguish these 2 tumor types. Recently, transcription factor PAX8 was shown to be a sensitive and relatively specific marker for Müllerian tumors. In addition, some studies suggest that h-caldesmon is sensitive and specific for mesothelioma when compared with serous ovarian tumors. The goal of this study was to evaluate whether PAX8 and h-caldesmon expression can successfully distinguish mesothelioma from serous ovarian tumors. Immunohistochemistry was carried out using PAX8 and h-caldesmon antibodies on archival tissue from 254 ovarian serous tumors and 50 mesothelial tumors. Nuclear and cytoplasmic immunoreactivity were considered positive for PAX8 and h-caldesmon, respectively. PAX8 staining was present in 99% of high-grade serous ovarian carcinomas and all (100%) low-grade ovarian carcinomas and serous borderline tumors; however, only 74% of these cases (188/254) were diffusely positive in more than 50% of tumors cells, and intensity ranged from strong to weak. None of the pleural malignant mesotheliomas were reactive with PAX8. However, 2/23 (9%) peritoneal malignant mesotheliomas showed focal and/or weak staining for PAX8; the remaining cases were negative. Two well-differentiated papillary mesotheliomas and 1 multicystic mesothelioma each showed some staining for PAX8. h-caldesmon was negative in all serous neoplasms and all mesothelial neoplasms, except 1 pleural malignant mesothelioma which showed patchy immunoreactivity. Strong PAX8 staining is highly specific (P<0.00001) for ovarian serous tumors when compared with malignant mesotheliomas of the peritoneum and pleura. The presence of weak staining for PAX8 in the 3 "noninvasive" mesotheliomas questions the use for PAX8 in this differential diagnosis. On the basis of this study, h-caldesmon is not a useful marker for mesothelioma.

Ovarian cancer is a leading cause of cancer mortality in women. The aim of this study was to elucidate whether whey acidic protein (WAP) genes on chromosome 20q13.12, a region frequently amplified in this cancer, are expressed in serous carcinoma, the most common form of the disease. Herein, we report that a trio of WAP genes (HE4, SLPI, and Elafin) is overexpressed and secreted by serous ovarian carcinomas. To our knowledge, this is the first report linking Elafin to ovarian cancer. Fluorescence in situ hybridization analysis of primary tumors demonstrates genomic gains of the Elafin locus in a majority of cases. In addition, a combination of peptidomimetics, RNA interference, and chromatin immunoprecipitation experiments shows that Elafin expression can be transcriptionally upregulated by inflammatory cytokines through activation of the nuclear factor kappaB pathway. Importantly, using a clinically annotated tissue microarray composed of late-stage, high-grade serous ovarian carcinomas, we show that Elafin expression correlates with poor overall survival. These results, combined with our observation that Elafin is secreted by ovarian tumors and is minimally expressed in normal tissues, suggest that Elafin may serve as a determinant of poor survival in this disease.

Objective: Prior studies have suggested that patients diagnosed with ovarian cancer at an older age have worse outcomes. However, few studies have examined whether differing patterns of protein expression in tumors in older patients correlate with this poorer prognosis. We investigated the correlation of age with prognosis and the significance of hormone receptor status in younger versus older patients through construction of a clinically-annotated high-density tissue microarray (HTMA) composed of stage III and IV papillary serous ovarian cancer cases., Methods: Two cohorts of patients (age > or =65 and < or =55 at diagnosis) were identified retrospectively from ovarian carcinoma pathology cases reviewed at our institution between 1999 and 2005. An HTMA was constructed from 148 eligible cases, and clinical data were abstracted through chart and database review., Results: No difference in survival was observed between younger and older patients. Patients > or =70 years had decreased survival on univariate, but not multivariate, analysis. ER was significantly more likely (p=0.01) and PR significantly less likely (p=0.02) to be expressed in older patients. Neither ER nor PR independently correlated with survival in the overall study population., Conclusions: Patients with advanced-stage papillary serous ovarian cancer > or =65 years of age at diagnosis have a similar survival as patients < or =55 years. Hormone receptor status differs significantly between the two age groups, and in the younger patient cohort, there is a trend towards longer overall survival for ER/PR positive tumors. These results suggest that ovarian cancer in younger patients differs biologically from that in older patients.

Summary: The embryonic stem cell transcription factors SOX2, NANOG, and OCT3/4 are involved in the regulation of germ cell tumor growth and differentiation. They, and D2-40 (podoplanin), an antigen expressed in seminomas, are emerging as useful diagnostic markers in testicular germ cell tumors. This study evaluates the use of these markers in ovarian tumors. Ovarian germ cell tumors (n=31) have distinct immunostaining profiles, depending on the type of differentiation as follows: dysgerminoma (SOX2-, NANOG+, OCT3/4+, D2-40+), embryonal carcinoma (SOX2+, NANOG+, OCT3/4+, D2-40-), immature teratomas (SOX2+, NANOG-, OCT3/4-, D2-40-), yolk sac tumors, and choriocarcinoma (SOX2-, NANOG-, OCT3/4-, D2-40-). In immature teratomas, SOX2 positivity was limited to neural and epithelial tissues, and OCT3/4 was positive only in scattered epithelial cells (<10% of cells). Nongerm cell tumors (n=57, including surface-epithelial stromal tumors and sex-cord stromal tumors) were negative for NANOG and D2-40. OCT3/4 was positive in 4 of 9 adult granulosa cell tumors (15% to 85% of cells). In a small number of surface-epithelial stromal tumors, SOX2 and/or OCT3/4 were variably positive (20% to 90% of cells). Of the markers, SOX2 and D2-40 discriminated between dysgerminoma and embryonal carcinoma. NANOG distinguished between either of these 2 tumors and nongerm cell tumors. The inclusion of these markers should therefore be considered in cases of pure or mixed ovarian germ cell tumors that are difficult to classify, and to exclude nongerm cell tumor mimics.

Purpose: To evaluate the possible mechanisms influencing the infiltration of CD8 T lymphocytes into the tumor epithelium of advanced-stage serous ovarian cancers., Experimental Design: Immunohistochemical localization of CD8 T lymphocytes was done on a homogeneous population of 184 high-grade, advanced-stage serous ovarian cancer tissue specimens. Microarray analysis was done on microdissected tumor epithelium from 38 specimens to identify genes up-regulated or down-regulated in specimens with differing numbers of tumor-infiltrating CD8 T lymphocytes. Quantitative real-time PCR and immunohistochemistry were used to validate a candidate gene. Univariate and multivariate survival analyses were done combining CD8 T lymphocyte number and HLA-DMB expression with standard prognostic factors., Results: Marked CD8 T lymphocyte infiltration of the tumor epithelium is associated with a 20-month improvement in median overall survival. Additionally, when combined with cytoreduction status and age, CD8 T lymphocyte status is an independent prognostic factor for survival. Microarray analysis showed HLA-DMB, a component of the MHC II antigen presentation machinery, to be differentially expressed in specimens with an abundance of tumor-infiltrating CD8 T lymphocytes. This relationship was validated at both mRNA and protein levels. As well, high HLA-DMB expression in the tumor epithelium was associated with a significant improvement in median overall survival in both univariate and multivariate analyses., Conclusions: Tumor cell expression of HLA-DMB is associated with increased numbers of tumor-infiltrating CD8 T lymphocytes and both are associated with improved survival in advanced-stage serous ovarian cancer.